91

Technically, yes, it would be easier to put people on Venus. You need less of a kick for the interplanetary trip and slowing down is trivial with that dense atmosphere...one of the Pioneer Multiprobe sub-probes made a soft landing despite only being designed as atmospheric probes. However, the surface temperature stays close to 464 °C, with over 90 ...


53

A brand new rocket to be launched will have to be assembled, and that's a long process, though I do not know how long. But if it's for an emergency, you may find ready rockets. After the Columbia disaster, space shuttle missions all had a contingency mission in case they found issues with the orbiter before reentry. The planning and training processes ...


52

Commercial Crew awarded two providers for dissimilar redundancy. This is exactly why NASA decided to select two partners in the commercial crew effort. Having dissimilar redundancy is key in NASA’s approach to maintaining a crew and cargo aboard the space station and to keeping our commitments to international partners. It also allows our private industry ...


49

As others have already pointed out, getting humans to Venus would be marginally easier than getting them to Mars. Let's consider survival on Venus in a little more detail though. Although there haven't been any manned missions to either Mars or Venus, there have been unmanned missions to both. So let's consider how long those unmanned missions have survived. ...


46

Assuming this isn't a troll question and you are serious about wanting to know what computers are used for in spaceflight (prior to 1988), NASA has a great resource for you: Computers in Spaceflight (PDF, 494 Mb) From the introduction: Computers are an integral part of all current spacecraft. Today they are used for guidance and navigation functions such as ...


38

All six successful landings were done manually, with the commander taking the controls at about 500 feet altitude. It was possible for the computer to complete the landing automatically, and Jim Lovell claimed that he was going to attempt that mode on Apollo 13, but all the commanders felt more comfortable in manual control in the final phase of landing. It'...


38

It always flew crewed. After the Columbia failure, provision was made to fly a damaged Orbiter uncrewed back to a west coast landing site, leaving the crew on the ISS. This was called the Remote Control Orbiter and it required an In-flight Maintenance kit to be installed after docking at the ISS. It was never used. The smallest number was two (STS-1, 2, 3, ...


37

They keep the ISS at a pretty comfortable temperature and humidity level, so there's not much sweat accumulation except when they're working out. For that, they use towels. The sweat that they do produce that evaporates (along with the water vapor they exhale) gets collected as part of the water processing system and recycled into drinkable water.


31

As I understand the livestream, the most important thing was pressure equalisation and subsequent leak checking. I guess this could be done faster, but it's just not worth taking any risks on it. Imagine there's some problem with the docking securing. As long as there's no pressure between the hatches, this wouldn't be seen (no mechanical load). Now as you ...


29

The pressures of both the Dragon spacecraft and the ISS match the atmospheric sea level pressure of Earth, about 1 bar. But there are small inevitable tolerances of about some millibar or less. So there is a non zero pressure difference between the spacecraft and the spacestation. When air temperature in the closed spacecraft changes by only 0.3 K, the ...


27

First of all, the ground team could have, and in fact did, do most of the orbital navigation remotely. This report mentions the fact that the on board computer was secondary for Apollo 8, with primary being systems from the ground. The spacecraft did have to do a few things, including making some realtime adjustments during the landing based on the actual ...


27

Your spacecraft would need to be several orders of magnitude larger than the Saturn-Apollo. No human pilot has successfully performed a rendezvous without a computer. Note that rendezvous is bringing two spacecraft close together in orbit, position, and velocity. Docking is the actual physical contact between two spacecraft. The latter can and often is ...


26

After the pointy-shaped object leaves, the remaining blunt-nosed rocket will experience dramatically enhanced structural loading and possibly aerodynamic instability. They expect a "rapid scheduled disassembly" in flight, but if that does not happen they will either let it blow up when it hits the ocean, or blow it up as @RussellBorogove suggests if it ...


25

Short answer: Yes. Mars is not windy enough to properly wave most flags. Long answer: In storm conditions, a flag constructed out of a very light material would be able to properly wave. If we take a standard flag, say 3'x5' that's made of 200g Nylon $\ell= 1.5$ meters $h_f = 0.9$ meters $W = A * 0.2 * g_{Mars}$, $W = 1$ Newton Going off the calculations ...


23

Let's look at Newton's first law: Law I: Every body persists in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by force impressed. In modern mathematical speech, this can be stated more precise. In an inertial frame of reference, an object either remains at rest or continues to ...


23

“Do I have a very naive concept of space travel?“ - honestly, yes you do. Here is an excerpt from Don Eyles’s wonderful book Sunburst and Luminary: An Apollo Memoir: Guidance would be processed every two seconds, repeatedly correcting and refining the trajectory based on new data from navigation. Into the guidance equation, with each turn of the crank, went ...


22

If you want an example manifest for one logistics flight, that's available. Search terms...suggest "ISS Cargo Manifest" From SpaceX 2 Cargo Manifest (see link for details) 81 kg of crew supplies (food, clothes, paperwork) 25 kg of international partner experiments 323 kg of NASA experiments 3 kg of EVA tools 135 kg of ISS hardware 8 kg of PC parts ...


20

According to an authoritative-sounding post on collectspace here, it's statute (which matches my recollection). Edit: OP @costrom found an FAA document Fact Sheet – Commercial Space Transportation Activities which confirms it.


19

Yes, NASA did consider a crewed flyby of Venus using Saturn/Apollo hardware. This is discussed in another QA on this site. There wasn't much point in doing it, as it would have been several months of flight for a very brief approach to Venus, in which the crew couldn't do much that a robot couldn't do much more cheaply and safely.


18

Given the mass costs in terms of consumables and the risk and support costs of keeping humans in space for longer, it seems unlikely that the multiple Earth-Venus flybys used by a lot of robot probes to get out to Jupiter or in to Mercury will ever be a sensible choice for humans. A Jupiter flyby on the way to Saturn is probably a no-brainer apart from maybe ...


17

The NASA requirement is 210 days. This is based on a nominal 180 day crew rotation. Source


17

This hinges as bit on what "as easy as" means. We clearly can't go to Mars today because we don't have the technology. We do have all the bits and pieces in theory, but we haven't build anything that can actually do it. SpaceX is famously trying to do exactly that with Starship/BFR. The discussed paper is Low-thrust trajectories for human missions to Ceres. ...


17

Signs point to no. There's an excellent overview of the rather complicated Apollo crew selection process in this answer: https://space.stackexchange.com/a/23149/6944 Then throw in this story of those offered Apollo missions who turned them down, which complicated the story even more: The Moonwalkers Who Could Have Been which states that Borman, McDivitt, ...


16

Are these statute miles (1609.344 m, 5280 ft) or nautical miles (1852 m, 6076-ish ft)? TL;DR Neither. Or rather, it is 50 statute miles, but a statute mile is not 1609.344 meters. That is the length of an international mile, and U.S. statutes have intentionally not made the conversion from survey miles to international miles. A statute mile is a synonym for ...


15

The entry vehicle for the Apollo missions is the command module (CM), which has a symmetric body with an offset center of gravity (c.g.). This offset c.g. causes the CM to trim aerodynamically at an angle of attack with a resulting lift force as illustrated in figure 1. The magnitude of the lift force is not controllable; ...


15

Yes, it was considered. The Command Module Pilot didn't have to die; the mere disability of the CMP was an issue. The earliest consideration of such a scenario was reported on August 25, 1964. The two major concerns were to stabilize the CSM's attitude and to turn on the docking radar transponder. The proposed solution was to allow ground control of both ...


15

According to a COLUMBUS Module engineer I once spoke with, it is common practise to use "silica gel" (the stuff in the small white bags you get buying new shoes or bags or everything) extensively because as you mention humidity is dangerous for everything onboard the ISS. I made a quick Google search for sources: Clearing the Air in Space: ...


14

The VASMIR 200 is listed as having a thrust of 5.4 newtons, and you need 9.8 newtons to lift 1kg against earth's gravity. So 700 tonnes is going to need more than a million engines and be consuming more than 254 GW of electricity. So even if the engines are weightless this is not lifting off from earth without co-opting the power generation of a sizable ...


14

For Gemini, Apollo, and Soyuz capsules, lift is achieved by offsetting the center of gravity of the reentry module from the center line of the craft. This is represented in your diagram by the "location of heavy equipment" callout, and results in the tilt of the capsule relative to the flight trajectory shown. The tilt causes the body of the spacecraft ...


14

Media reports about the discovery of an air leak on the ISS using a tea bag is rubbish, according to Russian cosmonaut Pavel Vinogradov. In an interview with Gazeta.Ru, he said that the journalists had misinterpreted the negotiations between the Russian station crew and the MCC specialists. “This is rubbish. Nothing was found with any tea bags. Here, of ...


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