# Tag Info

40

According to the link here, In meteorological rockets, the temperature sensor is not measured as the rocket ascends but a payload containing the sensor is ejected from a high altitude and as it parachutes down measurements are beamed back.

25

According to an article from the Lunar and Planetary Institute (archive.org link): As a result of the electrical disturbances experienced during the Apollo 12 launch, several experiments were performed prior to and during the launch of Apollo 13 to study certain aspects of launch-phase electrical phenomena. Measurements taken indicated a significant ...

22

To answer the question literally: you'd be looking for NASA Apollo Trajectory (NAT) data files. The report Apollo Mission 11, Trajectory Reconstruction and Postflight Analysis Volume 1 (PDF) provides a summary for Apollo 11 and mentions that the raw NAT data is available in Volume 2 of the report. I have yet to find Volume 2 though, perhaps because The ...

19

NEOs are mostly found as dots in images taken by various telescopes, often those of amateurs (as in not paid, nothing about skill or equipment). By taken repeated images days apart moving dots can be picked out against the static background stars and an orbit plotted. Then that orbit is matched against known objects, and used to either add a new object to ...

17

Introduction to selecting a reference surface The surface of any celestial body can be anything but uniform. The oceans, where existing, can be treated as reasonably uniform, but the surface or topography of the land masses can exhibit large vertical variations between mountains and valleys. These variations make it impossible to approximate the shape of ...

16

Yes, a properly functioning accelerometer that is stationary relative to the surface of the Earth will read the acceleration due to gravity. If it's a very good accelerometer, you could also see the factor of a few hundred smaller decrement in that acceleration due to the centripetal acceleration from the rotation of the Earth. If it's a really really good ...

12

Here is an answer from over on aviation.stackexchange.com which addresses this issue. I've quoted a portion of it below, but see that link for more info. As you measure temperature moving at high velocities, your outside thermometer will measure a higher temp than what is actually outside (what a non-moving thermometer would get). That's because as ...

12

For pretty precise measurement you use linear acceleration of the body with fixed force (say, spring pulled until its force reaches nominal value) and then you measure its speed when launched. Kinetic energy $E={{1}\over{2}}mv^2$ will be equal to potential energy of the "launcher" (which can be easily calibrated by launching an object of known mass and ...

11

I think you have it backwards - it doesn't matter where in the universe you are, absolute zero is still the same (-273.15°C) and the temperature increase marked by 1 Kelvin or 1 Centigrade is the same, so you could find a calibration point on any planet that came to the same temperature and list that as the way to measure 100°C etc. Realistically though, ...

11

Fuel requirements will probably dominate food and other consumables by an order of magnitude or more, so you can't save mass by shortening the trip. The exact tradeoff depends on the assumptions you make. I'm just going to consider the outbound leg of the flight. NASA's trajectory browser offers me two missions to Mars in the 2025-2035 timeframe: ...

10

You got caught by those silly English units. Your expression, $I_t = I_{sp}g_0 \dot m \Delta t$, works just fine when you use metric units. The mass flow rate, in metric units, is 127 kg/s. The total impulse, in metric units, is $$I_t = (217.5\,\text{s})(9.80665\,\text{m}/\text{s}^2)(127\, \text{kg}/\text{s})(65\,\text{s}) = 1.76\times 10^7\,\text{N}\,\text{... 9 Is it... the gravitational potential energy of one pound hoisted one foot in a constant gravitational field...? Yes indeed it is! To be energy, the pound has to be parallel to the foot.$$E = \int \mathbf{F} \cdot d \mathbf{s}$$To be torque, the pound has to be perpendicular to the foot$$\tau = \mathbf{r} \times \mathbf{F} 1 foot-pound (or pound ...

8

You can basically use all effects, that depend on the mass of an object. Spring pendulums, some magic with centrifugal forces, angular momentums ..... For determining the mass of for instance a human body, see Space Linear Acceleration Mass Measurement Device. There is some really cool website by NASA, which provides some nice insight and an experiment, ...

8

A quick search through the space agencies' sites yielded this photo of the IM-01M mass measuring device in the Russian orbital segment: Anatoly Ivanischin undertakes periodic weighing of his body on the "Mass measuring" device. Credits: Roscosmos. The likely author of the photo is Anton Shkaplerov. Peggy Whitson: We weigh ourselves with a Russian-built ...

8

The Apollo 11 EASEP handbook gives basic information on the first version. Of the LRRR, it has just two pages of text... There are some (poorly reproduced) images labelling the main parts. It's correct there is a sun "compass" and a level. The large part labelled "B" in the question is a rear support, presumably so the folded device could be stood on the ...

8

Here is a nice graph of part of what you are asking for. It's from the book Satellite Orbits; Models, Methods, Applications by Oliver Montenbruck and Eberhard Gill, Springer, 2000. The figure and description can also be found in google books. It shows the magnitude of some major perturbations acting on a satellite in earth orbit from LEO to GEO. This paper ...

7

Doppler and ranging are used routinely. They are both two-way, with the Doppler turning the frequency around and the ranging turning around a pseudo-noise signal. This is complicated, only for these spacecraft, due to the transmitting station on Earth rotating out of view (and in, and out again!) by the time the return signal hits Earth, being then received ...

7

Gravimetric Doppler measurements can actually confirm that Vesta has an iron core, as it eliminates the alternatives. This works in the following way: The mass of Vesta is first measured accurately, for example using the orbital period of a satellite, for instance the Dawn spacecraft. Then, based on observed geological features, its average density, the ...

7

In contexts in which there are virtually little relativistic effects, the current standard Coordinated Universal Time (UTC) would apply. As long as communication could be established with Earth, times could certainly be synchronized. In relativistic contexts, it doesn't make much sense to try to synchronize time. Instead, just give the time in that frame ...

7

The only form of ice that we see naturally in bulk on Earth is Ice I, all within the sub-h variety. There's no place on Earth that gets cold enough for any other form--but that's not necessarily true for the rest of the solar system. Unfortunately for this question, there is nowhere in the solar system that we could ever find any type of ice that depends ...

7

Actually, Ice VII has been discovered in diamonds on Earth. The water is first trapped in the diamond as the latter is formed deep in the mantle. Then when the diamond cools at the surface its rigid lattice retains the high pressure in the interior enabling the water to reach a combination of temperature and pressure where it forms Ice VII. The presence ...

7

The injection accuracy of the launch vehicle is typically measured in m/s, as the velocity change required to get the spacecraft exactly on the desired trajectory. This wraps up all the dimensions of the error (the energy, the trajectory plane, your time of arrival, etc.) into one number. From my recollection, that number is on the order of 1 to 10 m/s. ...

6

As described in extensive detail by Al Seiff and T.C.D. Knight in their May 1992 paper in Space Science Reviews, Vol 60; The Galileo Probe Atmosphere Structure instrument (which can be read without paywall by clicking "print this article"), the Galileo Probe measured atmospheric temperatures in Jupiter's troposphere with a platinum resistance thermometer (...

6

For Mars, the current definition of 0 km is derived from data from the Mars Orbiting Laser Altimeter (MOLA) data from Mars Global Surveyor. In fact the altitude reference is referred to as "MOLA altitude". You would say for example: "minus 1.4 km MOLA". From the paper: Zero elevation on Mars from MOLA is defined as the equipotential surface (...

6

LISA (long PDF) uses interferometry. This is a method that allows very accurate measurement of the difference between two lengths. Basically, a laser beam is split. Each half of the beam travels a different path. A small difference in path lengths causes a phase difference between the beams. Both beams are combined in a heterodyne detector, which produces an ...

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Here is a good tutorial on the navigation of deep space vehicles. The two main data types used are two-way Doppler (using an atomic clock reference at the DSN station, with the frequency locked to and sent back to Earth by the spacecraft), which gives the velocity component along the Earth-spacecraft line to better than 0.1 mm/s, and ranging (sending a ...

6

OSIRIS-REx is packed all full of good stuff. I'll throw together a quick list of the scanning ones you're interested in. Also of note is that the entire spacecraft will be making that scanning motion shown in the gif, so as the asteroid rotates, all of these instruments will be able to have full coverage of it. OSIRIS-REx Visible and Infrared Spectrometer ...

6

I'm not sure if I understand the basics behind this well enough to explain it but I'll give it a try anyway. I've looked mainly at this report and on the wiki on satellite temperature measurements. The basic measurement technique is using an infrared interferometer. The absorption and emission spectra that the instrument measures are dependent on the ...

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STEREO A and B, 2006-047A and B, (29510 and 29511) were launched together from "Cape Canaveral Air Force Station in Florida on a Delta II 7925-10L launcher into highly elliptical geocentric orbits". The elliptical orbits intercepted the Moon's trajectory, and because of a small but carefully design difference in their two positions, one was thrown ...

5

For spacecraft it's "where they fit and can be oriented properly". Harnessing constraints are somewhat considered (how do you get wires to it) and thermal constraints might be pretty important (ir telescopes need the detector to be very very cold so anything that produces heat is as far away as possible), but in general for satellites all motion is pretty ...

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