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34 votes
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How does one throw a boomerang in space? Does it return?

You throw it in space (in the ISS) just like you would in a room on Earth. It returns to you if it is properly built, and you are capable of properly throwing a boomerang to make it return (this does ...
JRE's user avatar
  • 813
20 votes
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How was "Space Ram" (instant ramen noodles) prepared and eaten on the Space Shuttle?

Like many dehydrated space foods, it's prepared by injecting hot water through a port in an otherwise sealed bag, manually mixing it by massaging the bag, and waiting a few minutes; the noodles are ...
Russell Borogove's user avatar
16 votes
Accepted

How are Kounotori modules unbolted? Who or what does the unbolting?

The bolts are part of the Common Berthing Mechanism (CBM). The Common Berthing Mechanism (CBM) is a complex collection of latches, bolts, Ready to Latch (RTL) indicators ... and computers to control ...
Organic Marble's user avatar
12 votes

How does one throw a boomerang in space? Does it return?

The return function of a boomerang works in the atmosphere only. Therefore no return in the vacuum of space. The 'arms' of a boomerang are profiled like a airplane wing, but wings do not work without ...
Uwe's user avatar
  • 49k
11 votes

How was "Space Ram" (instant ramen noodles) prepared and eaten on the Space Shuttle?

If the package on the right of the lower picture in the question was actually flown, it would have been heated in the Shuttle galley's "food warmer" / "oven". This is because it already contains ...
Organic Marble's user avatar
10 votes
Accepted

How is this reentrant storage area on JAXA's HTV 8 protected during launch?

It's all covered by a payload fairing that isn't flush with the body of the spacecraft. A picture is worth a thousand words:
Russell Borogove's user avatar
10 votes

If there "won't be" rockets to launch individual cubesats, then why did JAXA build exactly that? (SS-520-xx)

The SS-520-5 launcher is not intended to be an operational vehicle. ... the SS-520-5 was also an experiment to construct a minimum system that can be established with a micro-...
Organic Marble's user avatar
10 votes

How much of an advantage do equator-proximal launch sites provide?

I would like to add my own answer based purely on math, which is not as complex as you may think (but I explain each term and everything else so it looks long). We only need a couple equations. First ...
DrZ214's user avatar
  • 4,576
9 votes
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Why JAXA's tilted launch from a tilted rooftop?

The SS-520 lacks the guidance systems that more complex rockets have. It can detect where it is, and what it's attitude is, but can't make as many adjustments as more complex rockets. In order to make ...
PearsonArtPhoto's user avatar
  • 121k
8 votes
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DLR Mascot asteroid lander's unusual "torque wheel-based" propulsion system

If JAXA successfully deploys MASCOT, it will be the first lander to use "torque wheel based" propulsion. It is not, however, the first lander to be designed with such a system. JAXA's previous ...
A McKelvy's user avatar
  • 2,492
7 votes

Why did Hayabusa-2's capsule's parachute have transparent panels?

Assuming that the design of the parachute was the same as that used on the first Hayabusa, the section you mention is actually netting. The following description of the parachute was given when the ...
AlphaD's user avatar
  • 276
7 votes
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What is this black smoke coming from an all solid fueled Epsilon rocket?

It's the Solid Motor Side Jet (SMSJ) system used for roll control - and more! When you look at a picture of the launch, you will see black smoke being discharged from the SMSJ motors. They are ...
Organic Marble's user avatar
6 votes
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Would it be possible to "ride the wave" on Venus?

The density of carbon dioxide on Venus varies from about 67 kg/m3 at the surface to about 52 kg/m3 at a height of about 5 km, calculated with this software tool Image from Solar Powered Flight on ...
Cornelis's user avatar
  • 7,535
6 votes
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Fire pit at Tanegashima space center

They're burning off hydrogen in what is called a "flare stack". Probably the hydrogen boiled off from chilling down the engine and/or the hydrogen boiling off from the tank. These dim orange flames ...
Rikki-Tikki-Tavi's user avatar
6 votes

Could the Japanese H-IIB carry a payload to the moon?

Almost certainly. The predecessor H-IIA rocket delivered the orbiter SELENE to the moon in 2007. The SELENE-2 mission slated for 2018 or 2019 will use either an H-IIA or an H-IIB launcher -- it's not ...
Russell Borogove's user avatar
6 votes
Accepted

Will JAXA try again to launch TRICOM-1 with the "world's smallest orbital rocket" SS-520-4 again?

Yes! Update: Thanks to @Sean's answer, I've made an update here as well. From Wikipedia's S-Series_(rocket_family); SS-520-5 The second attempt at becoming the smallest orbital launching rocket was ...
uhoh's user avatar
  • 149k
6 votes

Nature of Hayabusa-2's "Home Position" relative to Ryugu? Is it Ruygu's L1?

Hayabusa2's Home Position, also known as BOX-A, is a cubic region approximately 1km in size, 20km above Ryugu and directly on the Ryugu-Earth line. We can show that the Home Position is not at any ...
Jack's user avatar
  • 9,956
6 votes

What antennas does JAXA use to communicate with its deep space spacecraft? Does it have a deep space network of its own?

Partial answer... Question: What antennas does JAXA use to communicate with its deep space spacecraft? From: https://www.isas.jaxa.jp/en/about/facilities/usuda.html (and mentioned in the comments to ...
blobbymcblobby's user avatar
5 votes
Accepted

How does the JEM/Kibo connect to the "Porch Module"?

The "porch" (formally the JEM-EF (Japanese Experiment Module - Exposed Facility)) had a matching connector on it that mated with the connector in the pictures above. This picture shows the shuttle arm ...
Organic Marble's user avatar
5 votes

How far did Hayabusa-2 back off before the "bomb" went off?

The answer is that the Hayabusa-2 was 4.61 km from the SCI when it detonated. The link provides a mission status briefing from JAXA which describes the entire sequence of events, including positions. ...
Anthony Stevens's user avatar
5 votes

MT-135 Sounding Rocket info / design

According to the JAXA page about the rocket, it's a solid-fuel motor: The propellant, a pre-formed grain, polyurethane composite with a low burning rate... By polyurethane composite I assume they ...
Russell Borogove's user avatar
5 votes
Accepted

What ion engine is used by Hayabusa2?

Searching for "hayabusa 2 thruster specifications" leads me to a paper titled Development and Testing of the Hayabusa2 Ion Engine System. The thruster is called µ10, four of them are used in a single ...
Russell Borogove's user avatar
5 votes
Accepted

From interplanetary space to the Australian Outback, how will Hayabusa2's return capsule be tracked? Desert Fireball Network perhaps?

There's a good description of the planned landing procedure in the news item, Japan's Hayabusa2 space capsule to fall back to Earth after six-year asteroid mission. Essentially human observers on the ...
Fred's user avatar
  • 13.1k
5 votes

Why did the maiden flight of H3 fail?

It's a bit premature to ask why a launch vehicle failed just a few days after the failure occurred. In this case, the second stage engine apparently failed to ignite. What caused that failure may not ...
David Hammen's user avatar
  • 74.9k
4 votes

Why JAXA's tilted launch from a tilted rooftop?

From the same article, a better photo of the launch site, showing the rocket on its launch rail next to the building: The JAXA site doesn't indicate why the rocket wasn't launched vertically. My ...
Hobbes's user avatar
  • 128k
4 votes
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How could JAXA not know when Hayabusa2 will arrive at asteroid Ryugu?

From spaceflight101.com: Hayabusa began firing three of its four ion engines again on January 10, 2018 marking the initiation of the far-field approach phase to take the spacecraft toward its ...
AtmosphericPrisonEscape's user avatar
4 votes
Accepted

Why did Hayabusa-2's capsule's parachute have transparent panels?

To confirm @AlphaD's answer, here are some pictures of peregrine parachute (はやぶさ パラシュート) from a Japanese image search. (Peregrine isn't the kind of parachute, it's English for Hayabusa.) They are ...
bandybabboon's user avatar
4 votes
Accepted

Osculating oscillations! What makes Akatsuki's eccentricity and inclination about Venus vary periodically?

The standard way to compute the time variation of the orbital elements starts from Lagrange's planetary equations. Other answers on this site which describe them are here, here, and here. These ...
Ryan C's user avatar
  • 7,962
4 votes

Osculating oscillations! What makes Akatsuki's eccentricity and inclination about Venus vary periodically?

Supporting @Ryan C's answer, here is that frequency domain representation of eccentricity: Where peaks are seen around the harmonics of a Venus year and the spacecraft's orbital period.
BrendanLuke15's user avatar
3 votes
Accepted

What is the US president talking about re US/Japan dramatic expansion of military(?) cooperation?

Historically, Japan has been involved in international space collaboration. They built the Kibo module on the ISS as well as lots of the surrounding science hardware, and a few Japanese astronauts ...
CourageousPotato's user avatar

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