Space Exploration newsletter

Top new questions this week:

Have we attempted to experimentally confirm gravitational time dilation?

Mark Adler wrote in an answer to a different question that We would expect that Voyager 1's local time is faster than Earth time by about one part in one hundred million. I don't think that ...

probe gravity time

asked by Michael Kjörling 34 votes answered by Mark Adler 52 votes

Why will GOES-R take a whole year for validation?

I've been reading a few things about NOAA's GOES-R satellite, and I noticed this on the GOES-R site: ...will be placed in the 89.5° checkout orbit where it will undergo an extended checkout and ...

artificial-satellite testing geostationary noaa

asked by duzzy 6 votes answered by David Hammen 6 votes

Schiaparelli 2?

From what I know, space scientists always work on two prototypes just in case something goes wrong. Why wasn't this the case this time? and are there plans for a repeat of this mission soon?

mars exomars

asked by Michael Papaioannou 5 votes answered by Mark Adler 4 votes

Could the solid boosters of SLS be replaced by reusable Falcon 9 first stages?

Is it feasible to redesign the Space Launch System to use a pair of reusable Falcon 9 first stages instead of the five-segment solid boosters now being developed? The reason would be to lower launch ...

spacex falcon-9 sls booster booster-flyback

asked by LocalFluff 5 votes answered by geoffc 6 votes

Why does the SpaceX first stage booster boost up and back after separation not just back?

By boosting up and back after separation aren't you just putting more energy in that you'll have to counter with additional deceleration later? Why not just accelerate back, which will use less ...

spacex landing falcon9-r

asked by user69911 5 votes answered by Hobbes 6 votes

EmDrive compared to flashlight in space

From my (basic) understanding the most impressive thing about the EmDrive is it violates Newton's third law. No propellant is needed, nothing is jettisoned away, yet it, allegedly, accelerates in a ...

propulsion advanced-propulsion emdrive

asked by Pyloid 4 votes answered by Nathan Tuggy 9 votes

Save energy in plane changing orbital maneuver

I just read about Cassini's upcoming orbital maneuvers where there's a nice animation showing Cassini's orbits. Here's a frame of the animation: I see a lot of plane changes, i.e. the probe's ...

orbital-mechanics orbital-maneuver cassini

asked by DarkDust 4 votes answered by Mark Adler 7 votes

Greatest hits from previous weeks:

What materials provide the best protection from cosmic radiation?

For long-distance manned missions, such as a mission to Mars, we are inevitably going to have to shield astronauts from cosmic radiation, especially in the event of a solar flare or SEP. What ...

crewed-spaceflight radiation materials

asked by Gwenn 11 votes answered by Robert Mason 12 votes

What is the fastest speed ever reached in space travel as measured from the point in space from which it was launched to its current/final position?

Answers.com lists the New Horizons to have the fastest rocket. Is this info still valid? 7 light hours in 11 years at 50,000 km/h?

spacecraft interstellar-travel pluto travel

asked by KingsInnerSoul 21 votes answered by EchoLogic 39 votes

Can you answer these?

Mars curiosity rover

I am trying to get information on the maxon drive motors on the Curiosity Rover. Does anyone A.) know what model of DC brushless motors are used B.) what kind of gear speed reducer is used. Is it a ...

mars spacecraft curiosity

asked by Ben Birdwell 4 votes

New Russian Sokol space suit

According to the pictures of the mission Soyuz MS-03, the crew is wearing a new "Sokol" space suit. The previous crew was still wearing the 1980 "vintage" KV2 version. Any information about ...

soyuz spacesuits sokol-spacesuit

asked by Covich 2 votes

Does a low-orbit communication network drive a sustainable launch market?

With SpaceX recent announcement of a huge satellite network in low earth orbit, I was wondering if such a network would motivate a sustainable large-scale launch capacity, i.e. a increase of scale of ...

spacex communication-satellite

asked by choeger 1 vote