Launching Paper Planes From Way, Waaaaaay Up

May 7, 2023 by Donald Papp 13 Comments

Every now and again we stumble across something a bit unexpected, and today that’s the fact that there have been quite a few efforts at launching paper planes from as close to space as possible. The current record for the highest paper plane launch is a whopping altitude of 35,043 meters.

That altitude is considerably short of what would be called “space”, but it’s still an awfully long way up and the air there is very thin compared to on the surface. Space is generally (but not universally) considered to be beyond 100 km above sea level, a human-chosen boundary known as the Kármán line. 35 km is a long ways into the stratosphere, but still within Earth’s atmosphere.

Even so, that doesn’t mean there haven’t been efforts to go considerably higher. There was a Japanese proposal to drop airplanes made from special heat-resistant paper from the International Space Station, roughly 400 km above Earth. Success would show that low-speed, low-friction atmospheric reentry is feasible — for pieces of paper, anyway. But one of the challenges is the fact that there is no practical way to track such objects on their way down, and therefore no way to determine where or when they would eventually land.

There have been many other high-altitude paper plane launches, but the current record of 35,043 meters was accomplished by David Green in the United Kingdom as part of a school project. Such altitudes are in the realm of things like weather balloons, and therefore certainly within the reach of hobbyists.

As for the airplanes themselves, the basic design pictured here probably won’t cut it, so why not brush up on designs with the Paper Airplane Design Database? Even if you don’t send them into the stratosphere (or higher), you might find something worth putting through a DIY wind tunnel to see how they perform.

The Forgotten Rescue Of The Salyut 7 Space Station

May 6, 2023 by Maya Posch 17 Comments

With only two space stations in orbit around Earth today in the form of the International Space Station and the Chinese Tiangong (‘Sky Palace’) station, it’s easy to forget how many space stations were launched in the previous century. And the Soviet Union launched by far the most, as part of the Salyut (Russian for ‘salute’ or ‘fireworks’) program. Although the program entailed both military (Orbital Piloted Station, or OPS) and civilian (Durable Orbital Station, or DOS) stations, it was the civilian stations that saw the most success, as well as the most daring rescue attempt with the recovering of the Salyut 7 space station.

Salyut 7 (DOS-6) was set to repeat Salyut 6’s success after its launch on April 19th 1982, until disaster struck in February 1985. Due to a series of electrical and other faults ground communication with the space station was cut off, and the at the time unmanned space station began to gradually tumble towards the Earth’s atmosphere. This left those in charge with two options: leave the station to burn up in the atmosphere, or stage a rescue mission.

Ultimately, on June 6th, 1985, Soyuz T-13 launched to rendezvous with Salyut 7. On board were cosmonauts Vladimir Dzhanibekov – who had previously manually docked with Salyut 7 – and Viktor Savinykh. Both men had done all they could to perform a manual docking and attempt to revive the stricken space station. Ultimately they managed to revive the station using what little charge was left in its batteries and the Soyuz’s thrusters, all the while braving freezing temperatures in the dead station’s interior.

Salyut 7 would continue to perform its duties until February 1991, with Mir (DOS-7, launched 1986) as the first modular space station taking over. The final DOS module (DOS-8) that directly traces its lineage to this era is still in orbit today as the ISS’ Zvezda module, keeping the Salyut legacy and the bravery of Dzhanibekov and Savinykh alive.

Virgin Galactic Cautiously Returns To Flight

May 4, 2023 by Tom Nardi 32 Comments

After Richard Branson delivered some inspiring words from his seat aboard SpaceShipTwo Unity, he unbuckled himself and started to float around the vehicle’s cabin along with three other Virgin Galactic employees. Reaching an apogee of 86 kilometers (53 miles), the passengers enjoyed four minutes of weightlessness during the July 2021 flight that was live-streamed over the Internet to an audience of millions. After years of delays, SpaceShipTwo had finally demonstrated it was capable of taking paying customers to the edge of space. As far as victories go — it was pretty impressive.

Yet despite the spectacle, weeks and months went by without an announcement about when commercial flights of the world’s first “spaceline” would finally begin. Now, nearly two years after Branson’s flight, Unity has flown again. Except instead of carrying the first group of customers, it performed the sort of un-powered test flight that Virgin Galactic hasn’t performed since 2017. Clearly, something didn’t go to plan back then.

The company is being as tight-lipped as ever, saying only that this test flight was necessary to “evaluate the performance of the spaceship…following the modification period.” The exact nature of these modifications is unclear, but for some hints, we could look at the New Yorker article from September 2021. It alleged that, unwilling to derail Branson’s highly publicized flight, Unity’s pilots decided not to abort their ascent despite several warning lights in the cockpit alerting them that the vehicle’s trajectory was deviating from the norm. Virgin Galactic later denied their characterization of the event, but the fact remains that Unity did leave its designated airspace during the flight, and that the Federal Aviation Administration grounded the spacecraft until an investigation into the mishap could be completed. Continue reading “Virgin Galactic Cautiously Returns To Flight” →

NASA’s Voyager Space Probe’s Reserve Power, And The Intricacies Of RTG-Based Power Systems

May 3, 2023 by Maya Posch 46 Comments

Launched in 1977, the Voyager 1 and 2 space probes have been operating non-stop for over 45 years, making their way from Earth to our solar system’s outer planets and beyond. Courtesy of the radioisotope thermoelectric generators (RTGs) which provided 470 W at launch, they are able to function in the darkness of Deep Space as well as they did within the confines of our Sun-lit solar system. Yet as nothing in the Universe is really infinite, so too do these RTGs wear out over time, both from natural decay of their radioactive source and from the degradation of the thermocouples.

Despite this gradual drop in power, NASA recently announced that Voyager 2 has a hitherto seemingly unknown source of reserve power that will postpone the shutdown of more science instruments for a few more years. The change essentially bypasses a voltage regulator circuit and associated backup power system, freeing up the power consumed by this for the scientific instruments which would otherwise have begun to shut down years sooner.

While this is good news in itself, it’s also noteworthy because the Voyager’s 45+ year old Multi-Hundred Watt (MHW) RTGs are the predecessor to the RTGs that are still powering the New Horizons probe after 17 years, and the Mars Science Laboratory (Curiosity) for over 10 years, showing the value of RTGs in long-term exploration missions.

Although the basic principle behind an RTG is quite simple, their design has changed significantly since the US put a SNAP-3 RTG on the Transit 4B satellite in 1961.

Continue reading “NASA’s Voyager Space Probe’s Reserve Power, And The Intricacies Of RTG-Based Power Systems” →

China's Chang'e-4 mission made the first-ever landing on the far side of the Moon in 2019. (Credit: Xinhua/Alamy)

Moon Mission Failures, Or Why Are Lunar Landings So Hard?

May 3, 2023 by Maya Posch 41 Comments

Given the number of spacecraft (both crewed and uncrewed) that touched down on the Moon during the Space Race it’s sometimes hard to imagine why today, with all our modern technology, our remotely operated vehicles seem to have so much trouble not smashing themselves to bits on the regolith surface.

This is the focus of a recent article in Nature that explores the aspects which still make soft landings on our closest space body so much harder than the tragic lithobraking as most recently demonstrated by ispace’s M1 lander.

So far only three entities have successfully landed a craft on the Moon’s surface: the government-funded space agencies of the US, USSR, and China. Of them, only China managed to do so on their first try in 2013 (Chang’e-3), and again in 2019 on the far side of the Moon (Chang’e-4). What is the toughest part about a Moon landing is not to get near the Moon, but it’s about getting close to the surface without getting lost. Since there are no navigation satellites beyond those you put up before the landing, and a lot of Moon dust that will be kicked up by any landing rocket engines, it can be tough to gauge one’s exact location and distance to the surface.

In the case of the ispace lander it would appear that it tragically ran out of propellant before it could safely touch down, which is another major concern. Both the US and USSR would smash Moon landers into its surface until the first successful landing in 1966, which makes the manned touchdown by Apollo 11 in 1969 even more impressive.

NASA’s Curiosity Mars Rover Gets A Major Software Upgrade

May 2, 2023 by Maya Posch 21 Comments

Although the Curiosity rover has been well out of the reach of human hands since it touched down on Mars’ surface in 2012, this doesn’t mean that it isn’t getting constant upgrades. Via its communication link with Earth it receives regular firmware updates, with the most recent one being the largest one since 2016. In addition to code clean-up and small tweaks to message formats, this new change should make Curiosity both smarter and have its wheels last longer.

The former helps to avoid the long idle times between navigating, as unlike its younger sibling, Curiosity does not have the dedicated navigation computer for more autonomous driving. Although it won’t make the 11-year old rover as nimble as its sibling, it should shorten these pauses and allow for more navigating and science to be done. Finally, the change to reduce wear on the wheels is fairly simple, but should be rather effective: this affects the amount of steering that Curiosity needs to do while driving in an arc.

With these changes in place, Curiosity should be all ready to receive its newest sibling as it arrives in a few years along with even more Mars helicopters.

ESA’s Jupiter-bound Probe Hits Antenna Snag

May 1, 2023 by Tom Nardi 27 Comments

While the few minutes it takes for a spacecraft’s booster rocket to claw its way out of Earth’s gravity well might be the most obviously hazardous period of the mission, an incredible number of things still need to go right before anyone on the ground can truly relax. Space is about as unforgiving an environment as you can imagine, and once your carefully designed vehicle is on its way out to the black, there’s not a whole lot you can do to help it along if things don’t go according to plan.

That’s precisely where the European Space Agency (ESA) currently finds themselves with their Jupiter Icy Moons Explorer (Juice) spacecraft. The April 14th launch from the Guiana Space Centre went off without a hitch, but when the probe’s 16 meter (52 foot) radar antenna was commanded to unfurl, something got jammed up. Judging by the images taken from onboard cameras, the antenna has only extended to roughly 1/3rd its total length.

The going theory is that one of the release pins has gotten stuck somewhere, preventing the antenna from moving any further. If that’s the case, it could mean jiggling the pin a few millimeters would get them back in the game. Unfortunately, there’s no gremlins with little hammers stowed away in the craft, so engineers on the ground will have to get a little more creative. Continue reading “ESA’s Jupiter-bound Probe Hits Antenna Snag” →