SpaceX's Fram2 returns from first-of-its-kind mission around Earth's poles | Hacker News Reader

SpaceX's Fram2 returns from first-of-its-kind mission around Earth's poles

cnn.com

39 pointsTMWNN31 comments

Named after the most successful polar exploring ship.

https://en.m.wikipedia.org/wiki/Fram_(ship)

If you could admire a ship, this would be it. It is on exhibit in Oslo.

It's not only exhibited but open to visitors, you can go inside it.

SpaceX is able to land spent rocket stages with precision. Way back the space shuttle was able to land at a precise point, (I read it was a nightmare to try to steer it)

Why are capsules still being dumped into the ocean?

Is there not a modern fancy way to make the capsules land on a runway?

I am pretty sure this is a dumb question for people wh know why but I am curious.

Just an (uneducated) guess here, I don't believe capsules carry the necessary amount of fuel that it would take to accomplish this.

The manned capsules, at least, have a launch abort system that was probably originally intended to evolve into landing-capable engines. They even released renders of it years ago.

https://en.wikipedia.org/wiki/SuperDraco

In fact, they can currently be used for propulsive landing… if the parachutes fail. https://www.nasaspaceflight.com/2024/10/dragon-propulsive-la...

There is a bigger safety margin for humans if you need to land in a relatively large area in the water somewhere with a larger range of acceptable velocities. I believe they considered a propulsive landing over land but decided against it to simplify the initial design.

10 years later though they have added this ability as a backup [0]. Which again shows how if human lives are on the line you want to favor redundancy and simplicity over flash.

0 - https://www.nasaspaceflight.com/2024/10/dragon-propulsive-la...

IIRC, the reason they rejected the land propulsive landing was that NASA insisted on more testing to certify it and SpaceX didn't want to bear the costs of those tests.

Given the parachute failures they had during initial qualifications and the subsequent delays and retesting costs there's a good chance they regret that decision.

Supposedly they retain the propulsive landing capability and could try to use it in an emergency if the chutes failed catastrophically. The thrusters needed for it have always been there because they are the same thrusters used for the launch escape system.

It's not 'supposedly'. It's a feature they officially gained just a few crewed flights back. It's a mean of last resort and has to be manually committed to during descend. I assume it may have to cut any remaining or semideployed parachutes.

I could be wrong but I don't think its been tested.

Capsules don't have wings so its hard to fly. SpaceX wanted to try propulsive landing on land, but NASA rejected it as unsafe. Inflatable landing balloons like Starliner was proposed, but it was rejected because it added complexity (needs a step to drop the heat shield before it inflates and also, needs a step to inflate the balloons)

It was the simplest choice

I think it boils down to the fact that water is softer than land, if anything goes wrong.

The Soviets did land most capsules on land, but those were very bumpy landings.

Soyuz still lands on land. Starliner landed (and will land) on land. Blue Origin's non-orbital ship lands on land.

Another benefit of water landings is you don't need to carry shotguns in the capsule to defend from bears.

The Space Shuttle had the benefit of having some lift and some controlability via control surfaces (elevons and a rudder).

While it had a famously terrible glide ratio, it did glide, and this meant that it could use these control surfaces to steer without needing to carry or burn extra fuel -- which is very important in a weight-critical field like spacecraft design.

Capsules don't produce any lift, for all practical purposes. They can't be steered using control surfaces, at least not in the same way as the Shuttle orbiter; their best means of slowing down are either a chute or soft-landing boosters, or both.

Chutes are subject to the wind, while soft-landing boosters fire only a few feet above the ground, and neither give any real steering ability. Between this and trajectory variations on re-entry caused by wind throughout the atmosphere, you can't achieve the same level of precision when landing a capsule compared to the Shuttle orbiter.

Capsules do generate lift by having a slightly offset center of mass and control its orientation by rolling the entire capsule. This is used since the Apollo days to steer to the landing site. Even mars rovers use capsule lift during mars entry to steer.

Indeed, there's some neat old school diagrams showing how the capsule lift worked. It's a bit unintuitive at first, but if you have a blunt/rounded object traversing the atmosphere at a few times the speed of sound, slightly shifting the CoM around and tilting/rolling the capsule can dramatically affect the landing site.

Adding fuel and engines to turn the last stage into a lander adds a lot of weight that has knock-on effects resulting in the launch vehicle needing to be much, much bigger for a given payload. Combined parachute and descent thrusters might be light enough, but I don't think that's ever been done for a human landing. Plus, if a chute fails but you still have fuel, the landing goes from being potentially rough to potentially explosive, which is much worse from a PR perspective for a crewed lander.

The engines and propellant are already in the Dragon capsule, for the launch escape system. These are, at least in theory, capable of propulsive landing but that mode of operation hasn't been fully tested and certified.

Different crew vehicles have different capabilities. Dragon is similar to Soyuz, Apollo, et al. It doesn't have a lot of maneuverability on the way down -- and if it lands in the ocean, it doesn't need it. (Soyuz lands on land; again, if it's off target it's no big deal.)

I think there were designs for a version of Dragon that could do propulsive landings, but that was abandoned.

Assuming they get Starship working reliably, it will do precise landings, probably with a tower catch, eventually with a crew on board.

Soyuz is single use: if the capsule gets banged up a bit on a hard earth landing, it's not a problem (well, assuming the people inside survive).

Dragons are reusable, and Fram2 was in fact the fourth mission of the same vehicle. So they need to be treated with kid gloves.

Call me superstitious, but that's one of the things stopping me from taking a tourist spaceflight (together with the nausea and, well, price).

These capsules don't look that seaworthy, and sinking in one seems like a really terrible and expensive way to go - like that Mercury capsule.

I bet it has great buoyancy and is difficult to sink. They onyl open it on the ship, after washing off hypergol remains and going over it with a chemical sniffer.

They only land in good weather. I've watched many livestreams of landings, it always looks calm. The people attaching the ropes don't seem bothered. The astronauts inside are not too sea sick.

I like how one of the astronauts just nonchalantly tweeted every 30 minutes or so, like he wasn't in space.

Being on that flight while Tweeting via Starlink that you just used PayPal to order a new Tesla would be peak Musktech.

It's surprising how little media attention this got. Sketchy Chinese crypto billionaire notionally resident in Svalbard with six passports of convenience charters a space mission for funzies, and nobody even notices, much less digs into who this guy is. The closest is this softball interview by the Times of Malta, one of his six passports:

https://timesofmalta.com/article/meet-chun-wang-first-maltes...

(Although to be fair, there have been a couple of other distractions in the news last week.)

I'm really surprised that "the first x-ray taken in space" has occurred this late in the game, given what we know about what being in space on the longer term does to you.

I had thought the Polaris Dawn mission did this a few months ago, but apparently that was ineptly named.

Inspiration4 was the first private civilian mission on SpaceX Crew Dragon.

Polaris Dawn was a test flight of SpaceX's in-development extravehicular activity space suit, tethered to the spacecraft (so not like NASA EMU) but in vacuum.

Fram2 was the first crewed mission in polar orbit, with good view of the North and South poles. Other crewed missions were in less inclined orbits, usually the same inclination as the ISS or as Cape Canaveral.

Slight correction, NASA's EMUs don't use life support umbilicals, but astronauts are meant to always be tethered (safety strap, not life support) while using them. They have SAFER thruster packs as a backup should anybody ever become untethered, but the utility of these is dubious. NASA has done deliberate totally untethered EVAs before, but AFAIK not since the 1980s, as the MMU (SAFER's larger predecessor) was retired after Challenger.

The SpaceX suits used so far do have life support umbilicals.

Chun Wang said that his first choice for the name of his flight would have been Polaris had Jared Isaacman not already used it.

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