45
votes
Sending rockets to space will eventually consume all of our resources?
Most of the propellant expended in sending a spacecraft to Mars immediately returns to Earth -- the fuel and oxidizer are combusted, combining into (typically) water vapor, CO2, and other simple ...
- 170k
40
votes
Is it possible that Curiosity Rover measured its own methane or failed doing the spectrometry?
I am Jose Juan Lopez Moreno, co-I (co-investigator) of TGO-NOMAD and I feel obliged to respond to PearsonArtPhoto's answer.
There is something real: TGO carries 2 independent instruments with a ...
37
votes
Accepted
Is it possible that Curiosity Rover measured its own methane or failed doing the spectrometry?
There's a lot to unpack here, so let's look at the various discoveries of methane on Mars.
The first discovery came from multiple groups in 2003-2004 using first Mars Express, followed by Earth ...
- 122k
19
votes
Accepted
Why RP-1 and not Methane for Falcon 9's Merlin engines?
SpaceX chose to use RP-1 because the development path for a good RP1 engine was a full decade shorter! Plus many other factors favoring KeroLox for launch from Earth surface, for example the very high ...
12
votes
Accepted
What exactly are the recent observations of organics on Mars? What's the data?
There are currently (June 2018) two new papers (links may be paywalled):
"Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars", Eigenbrode et al., Science 360, 1096–1101 (...
- 12.8k
11
votes
Sending rockets to space will eventually consume all of our resources?
There is far more material to be gained from space exploration than will be lost from Earth in collecting it.
A primary reason to explore space is to exploit mineral and organic resources that occur ...
- 622
8
votes
How did JPL detonate a liquid oxygen methane mixture with light?
At low temperatures, the activation energy for pure CH4 O2 oxidization is about 170kj/mole. (See figure 1 here) That’s about 1.8eV per atomic reaction.
1.8eV can be provided by 688nm red light, or ...
- 12.8k
8
votes
Accepted
How will Robotic Refueling Mission-3's liquid methane tank remain full for six months without any boil off?
Image from the informative presentation Progress on the RRM3 Cryogen Demonstration System
The cryocoolers were commercial units, electrically powered Sunpower Cryotel CT 11 watt units. There is a ...
- 188k
8
votes
How much methane to push Titan into Saturn?
Let's turn the question on its head and see what exhaust velocity we need to if Titan's entire (mostly nitrogen) atmosphere were used as a propellant.
$\Delta v = v_e log(m_i / m_f)$
Wikipedia tells ...
- 421
8
votes
Why do methane engines require burn-off igniters?
Whilst methane is indeed less flammable than hydrogen there is still a very real risk of unburnt methane accumulating under the vehicle during engine chill down. Space X thought this wouldn't be a ...
- 2,405
7
votes
How much methane to push Titan into Saturn?
Let's do a Fermi estimate:
Rockets bring about 2-5% of their start mass to orbital velocity. To cancel out Titan's orbital velocity, you're looking at two orders of magnitude more fuel and oxidizer ...
- 128k
7
votes
Does methalox fuel have a coking problem at all?
Methalox produces the least coking of any hydrocarbon rocket fuel.
Coke is a compound of almost pure aromatic carbon rings, whose chemical structure resembles chicken wire.
Coke is formed by the ...
- 24.9k
6
votes
Accepted
Why are there no methane detectors with "the mole" of the Insight lander?
The reason is because it wasn't part of the science objectives. It is a Discovery Mission, which has a constrained total budget to start with, and what was selected was very close to a build-to-print ...
- 851
6
votes
Accepted
Conditions on Titan under which human breath can be set to fire
Wikipedia says of the composition of the lower atmosphere:
Because methane condenses out of Titan's atmosphere at high altitudes, its abundance increases as one descends below the tropopause at an ...
- 19.6k
5
votes
Accepted
Were there any experiments that produced rocket fuel grade methane on mars?
To my knowledge, while a variety of institutions have looked at producing Methane on Mars by combining native CO2 with imported H2 using the Sabatier Reaction, no experiments have actually been ...
- 4,484
5
votes
Accepted
Methane on Mars - Can we locate the source?
Would it be possible to pinpoint the source of the Methane with current technology
Yes. The purpose of ESA's ExoMars Trace Gas Orbiter mission is to locate the sources of trace gases, including ...
- 566
5
votes
Accepted
NASA's Curiosity Rover - Carbon Isotope Ratio of Methane?
I know Chris Webster (at JPL) well and have discussed the TLS instruments he builds at length. They have more in common with the MIRO instrument on the ESA Rosetta spacecraft (I was a co-investigator ...
- 18.3k
5
votes
What are SpaceX plans for Starship with respect to Moon landing and then takeoff?
The Lunar Starship will have to be refueled from Earth, for each mission, and will brings its fuel for return with it, when it lands.
As noted, while there may be Hydrogen available in ice in craters, ...
- 80.2k
5
votes
Why RP-1 and not Methane for Falcon 9's Merlin engines?
The first methalox engine I've been able to find, the RS-18, was developed two years after the first flight of Falcon 1 and the Merlin engine. In contrast, RP-1 had a half-century of development ...
- 15.7k
5
votes
Why RP-1 and not Methane for Falcon 9's Merlin engines?
Because in 2002 there were no existing methane engines they could use or copy (at least none suitable for a booster).
SpaceX didn't have the time or money to develop a whole new engine using a whole ...
- 2,350
5
votes
Does methalox fuel have a coking problem at all?
That would suggest it doesn't occur in the range from 880 K to 1103 K, at whatever pressure they were testing at. Also, from a few sentences later:
Deposition of carbon on the surface was observed at ...
- 10.9k
4
votes
Why are there no methane detectors with "the mole" of the Insight lander?
In part because an actual methane only sensor is hard to build. The standard ones you can buy have a range of things that make them false positive*, and the older hot wire ones need oxygen at a known ...
- 23.4k
4
votes
How would the Saturn V have differed if the first stage was using liquid methane and LOX?
Methane/LOX specific impulse is only slightly better than kerosene/LOX and it's about 25% less dense. In this case I think stretching the first stage would be more likely than fattening it; ...
- 170k
4
votes
Sending rockets to space will eventually consume all of our resources?
Eventually, NASA is planning on making a moon base and they will then make rocket fuel out of the water there. We could also make fuel out of the oceans which would solve this problem.
Here are some ...
- 65
4
votes
Accepted
Are there fuel cells for methane + oxygen? Could there be?
This 2018 release from Georgia Tech describes one such - claimed to be more practical than previous methane-fueled cells because it operates at a lower temperature. It is a solid-oxide cell.
It ...
- 188k
4
votes
What are SpaceX plans for Starship with respect to Moon landing and then takeoff?
The whole Starship system is built around two fundamental ideas:
Robotic refueling and
A large fleet of cheap, aggressively simple, mass-produced, mostly identical vehicles driving cost down. Even ...
- 20k
3
votes
Is it possible that Curiosity Rover measured its own methane or failed doing the spectrometry?
July 2021 update: It's a daily variation, not an instrument problem
A NASA article explains that the difference between the methane measurements of Curiosity and the Trace Gas Orbiter is due to the ...
- 48.2k
3
votes
How does methane waste produced by the ISS interact with our Atmosphere?
Assuming the methane stays in orbit around the Earth as indicated by uhoh, it will then not do much else. Wikipedia has a fairly extensive article about methane in the atmosphere, and it mentions ...
- 8,615
3
votes
Spacesuit needed for 1 psi 100% methane atmosphere - 60 Fahrenheit?
A pressurized space suit is needed when the atmospheric pressure is lower than about 0.3 to 0.4 bar. Pure oxygen is breathed within the suit. So for about 0.07 bar a pressurized suit is mandatory.
...
- 49.3k
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