Design of Multi-Purpose Satellite Buses

A multi-purpose satellite bus is designed to accommodate several different payloads for various space missions. Thus, instead of focusing on a single mission goal like Earth observation or meteorological forecasts, a single spacecraft bus can carry out a set of different tasks, thus reducing the costs of a space mission. No doubt, there are certain peculiarities satellite bus manufacturers will have to consider when designing a multi-purpose platform, but this extra effort is well worth it considering the pace of our space exploration efforts today. So, let’s take a better look at satellite buses, their goals, designs, and objectives they can accomplish.

What is the function of a satellite bus? 

Satellite buses are platforms that host all electronic equipment necessary for the spacecraft’s proper functioning. The satellite can be set to perform all sorts of tasks, from taking pictures of our planet to sending navigational data back to earth. Regardless of the actual mission objective, the main function of each and every satellite bus out there is to ensure that a satellite copes with its goals correctly. To this end, satellite buses carry payloads necessary for a spacecraft to work. This could be a rather complex structure, including computers, thrusters, and trusses to hold all of that equipment together. But why is it called a satellite bus? Mostly because all of that equipment is placed on a single, usually elongated, platform. The term is not space-technology-exclusive because you can find buses in other complex machines, for example, industrial freight cranes. But let’s take a better look at satellite bus design and structure.

Satellite Bus System Design & Main Components

Despite some minor variations that depend on the spacecraft’s purpose, a typical satellite bus structure includes a set of standard components, such as:

  • Computer to ensure command and control from the ground station
  • Transmitters sending signals to the ground stations
  • Trusses connecting multiple payloads together
  • Thermal control systems to maintain proper spacecraft temperature
  • Thrusters and other necessary propulsion systems to make sure the spacecraft can adjust its position when necessary

Those systems are absolutely essential for any satellite bus, no matter which particular function the spacecraft caters to. The additional payload may include various sensors, radar, and other equipment necessary to fulfil mission goals. 

The more objectives the spacecraft has to meet, the more complex the satellite bus structure can get — especially so when it comes to electronics. Often different payloads installed on a multi-purpose satellite bus require a different power supply and, consequently, voltage. So, when wondering — ‘What is satellite bus voltage?’ Always keep in mind that there is no rigid universal parameter. So far, 28 VDC is the most common figure, but the actual satellite bus voltage can be higher or lower than this widespread figure.

Alternative Configurations

Satellite Bus Design

Any multi-purpose satellite bus (MPS) can accommodate at least two, possibly more, payloads. Often, payloads may have different configuration requirements, not only when a power supply is concerned. For example, payloads will have to be ‘matched’ in terms of axis control, altitude parameters, and even thermal requirements. Let’s consider an example when a satellite bus manufacturer intends to combine meteorological forecasts with high-frequency communication.

Traditionally, meteoritical satellites would have to be placed in sun-synchronous orbit, while communication ones — in a highly elliptical orbit. However, experiments with multi-purpose satellite buses, including studies from NASA, have proven that these two can be ‘reconciled.’ In this particular example, the spacecraft would have to use two different axes and two different altitude control systems.

Another challenge when configuring MPS is thermal control, as different payloads may have different specifications here, too. Any payload with infrared sensors, which is a common parameter for weather and EOS spacecraft, must maintain a specific temperature range to ensure its functionality. Communication spacecraft are often less picky in this regard, but generally, altitude control and thermal systems pose the greatest challenge for bus manufacturers.

The final critical parameter is the weight of the final assembly. Today, most satellite buses are roughly divided into three categories depending on how much payload they can carry. One might assume that the more a spacecraft can carry, the more versatile it is going to be. In practice, this is not always so. Often, more lightweight electronics can cope with more functions than large, heavy onboard computers and sensors.

All in all, spacecraft technology is evolving rather rapidly, and today’s buses can carry out more than just two different purposes. Besides, there is a strong tendency to tech miniaturization, which means that most spacecraft components become smaller even when their functionality increases. So, perhaps at some point in the near future, we will not have to talk about single-purpose satellites as the new generation of spacecraft will be able to cope with several tasks at once.

SpaceX fails to make orbit but remains a successful launch

SpaceXSpaceX is a private American aerospace company founded by Elon Musk in 2002 with the goal of making space travel more accessible and affordable.

The company designs, manufactures, and launches advanced rockets and spacecraft with the aim of colonizing Mars and making humans a multiplanetary species.

One of its most notable accomplishments is the development of the reusable Falcon 9 rocket and Dragon spacecraft, which have been used to deliver cargo and astronauts to the International Space Station.

SpaceX’s ultimate goal is to create spaceships capable of transporting people to the Moon, Mars, and other planets, making human exploration and colonization of other worlds a reality.

Failure to launch

On Thursday, SpaceX waited to see Starship, the company’s latest project, take off.

Although the massive stainless steel vessel took off from its launch site at Boca Chica, Texas, it failed to make orbit.

According to’s Stephen Clark, around five of its 33 Raptor engines didn’t fire during lift-off.

The rocket managed to clear the launch tower and shoot for the sky.

However, the spacecraft failed to detach from the Super Heavy booster before the vessel started spinning.

Eventually, Starship fell apart in what is technically known as a “rapid unscheduled disassembly.”

The massive launching system stood at 394 feet tall (120 meters), which towered higher than the Statue of Liberty in New York City.

“The vehicle experienced multiple engines out during the flight test, lost altitude, and began to tumble,” SpaceX said in an update.

“The flight termination system was commanded on both the booster and ship.”

The Federal Aviation Administration released a statement on Thursday afternoon, saying:

“An anomaly occurred during the ascent and prior to stage separation resulting in a loss of the vehicle. No injuries or public property damage have been reported.”

“The FAA will oversee the mishap investigation of the Starship/Super Heavy test mission.”

“A return to flight of the Starship/Super Heavy vehicle is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety.”

“This is standard practice for all mishap investigations.”

Read also: Tesla price war leads to Chinese EV makers losing profits

One step forward

While it failed to hit orbit, Starship’s successful takeoff indicated a step forward in the United States goal to achieve space travel.

SpaceX foresees the vessel as a key link in a manned mission to help humans one day reach Mars.

Furthermore, the lift-off set a new record for being the largest rocket to ever launch.

SpaceX CEO Elon Musk tempered expectations before the lift-off, saying:

“Success is not what should be expected… that would be insane.”

Following the explosion, the company tweeted:

“With a test like this, success comes from what we learn, and today’s test will help us improve Starship’s reliability as SpaceX seeks to make life multi-planetary.”

Meanwhile, Musk congratulated members of the team for the “exciting” test launch, saying they learned enough for the next test launch.

“I don’t want to jinx it, but I think we are highly likely to reach orbit this year and recover the booster and ship, if not this year, certainly next year,” he wrote in an email to employees.

“Mars, here we come!”

Another attempt

In anticipation of the next test launch, SpaceX would need to obtain a launch license from the FAA.

The company believes it won’t be as troublesome as it was for the Thursday launch.”

NASA Administrator Bill Nelson also seemed enthusiastic, congratulating the team for the flight test.

‘Every great achievement throughout history has demanded some level of calculated risk, because with great risk comes great reward,” Nelson tweeted.

‘Looking forward to all that SpaceX learns, to the next flight test — and beyond.”

NASA’s Artemis I Mission Encounters Another Problem, Takeoff May be Delayed by Months

After a second problem encountered by NASA’s launch team last Saturday, the Artemis I may not make the full mission as planned.

The vessel is slated for future missions — in September and October. However, with the new conditions giving doubts to the team, there may be delays with the aforementioned schedules. According to NASA, the delays could be from days to a couple of weeks, depending on the assessment from the launch team of Artemis I.

Jim Free, the associate administrator from the Exploration Systems Development Mission Doctorate of NASA, said, “We will not be launching in this launch period. We are not where we wanted to be.”

The vessel, composed of the Orion spacecraft and the Space Launch System rocket, needs to be brought to and checked by the Vehicle Assembly Building, where it will await a waiver from the US Space Force before it is cleared for its next mission.

The administrator of NASA, Bill Nelson, said that the scrubs the team encountered do not mean Artemis I is a failure. He told the media that Artemis had already been checked and reassessed by the Vehicle Assembly Building 20 times before its planned launch.

“We do not launch until we think it’s right,”said Nelson. “These teams have labored over that, and that is the conclusion they came to. I look at this as part of our space program, in which safety is the top of the list.”

The scrub that hindered the mission

Three hours before its planned launch last Saturday, Artemis I received a call for scrub from the members. A liquid hydrogen leak was discovered by the members. The team then checked and spent time resolving the issue.

Liquid Hydrogen is an essential requirement for takeoff since it is used as one of the propellants in the rocket’s large core. The leak within the Artemis I system suspended the takeoff of the vessel even with several troubleshooting initiatives undertaken by the team.

A small leak found in the same area was also found prior to the Saturday takeoff, but the one they found on the day of the launch was much bigger. According to the initial diagnosis, the soft seal of the liquid hydrogen connection might have been damaged due to overpressurization. However, the team said they need to make more assessments to ensure that everything is accounted for.

One of the other problems

Artemis mission manager Mike Sarafin had to make sure that all was in order before the launch was called. And in doing so, permitted to delay the takeoff numerous times because of several issues that arose. The hydrogen leak is just one of many problems the Artemis team dealt with.

Issues with the rocket’s cooling system, persistent leaks, and other minor issues were causes for the delay. Artemis I had been suspended twice because of these problems.

NASA said that the bigger leak on Saturday prompted the team to “close the valve used to fill and drain it, then increase pressure on a ground transfer line using helium to try to reseal it.”

Despite efforts to stop the leaking, it reoccured, leading the Artemis team to call off the launch plan. Further, weather officer Melody Lovin reported a 60% chance of favorable weather conditions.

The Artemis I and its goal

NASA has prepared for this mission for a long time because, if successful, NASA could set the conditions for another manned mission to the moon and, more ambitiously, to Mars.

Nelson said, “As we embark on the first Artemis test flight, we recall this agency’s l storied past, but our eyes are focused not on the immediate future but out there.”

“It’s a future where NASA will land the first woman and the first person of color on the l moon. And on these increasingly complex l missions, astronauts will live and work in l deep space, and we’ll develop the science and technology to send the first humans to Mars.”

Source: CNN

Artemis I: NASA’s Precursor for Another Manned Space Flight to the Moon 50 Years After Apollo

After almost 50 years, humanity is now again preparing for a manned flight to the moon. With the help of a team of experts and scientists at NASA, the famed Apollo mission will soon be superseded by another ambitious flight to the Earth’s natural satellite – the Artemis I.

The Artemis program, named after the twin sister of Apollo, will make its way to the moon and land on where Apollo last ventured. The team is expected to travel across unexplored lunar regions. Looking ahead, NASA hopes that the Artemis missions will make it to the surface of Mars.

For the first time, humans would discover what is in the shadowy regions found south of the moon. The Artemis mission intends to find a stable area where astronauts could stay for extended periods of time and use findings to help in plans to shoot to Mars.

Over a month ago, NASA’s rover discovered stable pits on the surface of the moon where the temperature is stable and could support human life. Unfortunately, due to the volatility of the moon’s surface, astronauts have had a difficult time staying on the moon’s surface for a long time. However, with the discovery, NASA is confident that the Artemis I could achieve what it came for.

Read Also: The Mental and Physical Benefit of Swimming, a Good Activity During a Scorching Summer

What the Artemis I mission is

The Artemis launches on August 29. To ensure the safety of possible humans going into the intended region, the first flight would be unmanned but highly observed. NASA will lead the operations of Artemis I and check every factor that could help the agency come up with measures and countermeasures to guarantee smooth flight of the manned missions of Artemis II and Artemis III.

The subsequent missions will be based on the findings of Artemis I. NASA says that Artemis II will be launched in 2024, then Artemis III the year after.

The liftoff will commence at around 8:33 a.m. and 10:33 a.m. ET this August 29 from Florida. As expected, Americans would make their way to the Kennedy Space Center, where people could see the spectacle as the mission will start.

After liftoff, Artemis I will embark on a 42-day voyage where it will travel 40,000 miles beyond the moon, thanks to the Orion spacecraft. If successful, the journey will be farther than what Apollo has achieved. It is important that NASA oversees the mission since Artemis I’s path would be the same journey that the manned Artemis II will take.

Read Also: Bed Bath & Beyond to Boost Sales and Investors Confidence in New Strategy

NASA’s pride

“As we embark on the first Artemis test flight, we recall this agency’s storied past, but our eyes are focused not on the immediate future but out there,” said NASA Administrator Bill Nelson.

“It’s a future where NASA will land the first woman and the first person of color on the moon. And on these increasingly complex missions, astronauts will live and work in deep space, and we’ll develop the science and technology to send the first humans to Mars.”

The Space Launch Rocket System propelling Artemis I to the moon is a design based on all the information and data from the Apollo mission. The rocket could carry the craft a thousand times farther than the low-Earth orbit location of the International Space Station. Further, the rocket will speed up the Orion up to 22,600 miles per hour.

“It’s the only rocket that’s capable of sending Orion and a crew and supplies into deep space on a single launch,” said the program manager of the SLS, John Honeycutt.

“It’s the powerhouse side of the vehicle where it’s got the primary propulsion, power and life support resources we need for Artemis I. Re-entry will be great to demonstrate our heat shield capability, making sure that the spacecraft comes home safely and, of course for future missions, protecting the crew,” added the Orion program manager of NASA, Howard Hu.

“Artemis I shows that we can do big things, things that unite people, things that benefit humanity — things like Apollo that inspire the world,” Nelson added. “And to all of us that gaze up at the moon, dreaming of the day humankind returns to the lunar surface: Folks, we’re here, we are going back, and that journey, our journey, begins with Artemis I.”

Source: CNN