Voskhod Spacecraft "Globus" IMP navigation instrument
Globus IMP instruments were
The IMP, in successively developing versions, has been used in Soviet and Russian crewed space missions ever since the world's first crewed spaceflight (Yuri Gagarin, 12 April 1961) through every crewed Vostok, Voskhod and Soyuz mission until 2002.
- This article specifically covers IMP Version 3, used in Vostok missions and subsequent versions for the more complex Soyuz. However all versions of the IMP were relatively similar with respect to design, purpose and operation.
Context and purpose
The
The design objectives for the IMP were to compute and display the geographic coordinates at the spacecraft's nadir, i.e. which point on Earth's surface it was overflying. The Globus displayed this data to the crew, and also transmitted electrical data to other systems through a variable resistance and cam-activated switching.[4][5][citation needed]
Derivatives of Vostok's and Voskhod's IMP have been flown on every
The Soyuz TMA spacecraft and its successors now provide similar functions to the Globus using a computerized world map on a computer display.[6]
The Russian early missions were mostly automated and controlled from the
However, the IMP would become crucial if manual retrorocket activation became compromised by failure of either the flight sequencer or communications with mission control, as did happen on Voskhod 2. Furthermore, given the scarcity of Soviet communication stations on Earth, the cosmonauts spent most of their time out of range with ground control and needed instruments to assess their position relative to the ground.[1][7][8]
By contrast, the US crewed space programs used a similar, mechanical positional indicator only during two of its early Mercury missions before discarding it. By 1961 under project Project Gemini the US crewed space program changed to fully autonomous digital computerized systems. These systems consisted of gyro platform, digital computer and fly-by-wire systems.[9] The first being the Gemini Guidance Computer. The computer was architecturally similar to the Saturn Launch Vehicle Digital Computer, in particular in the instruction set; however its circuit integration was less advanced.[9][10] Later, for the Apollo program NASA, under the lead of MIT's Instrument Laboratory will use the first digital computer using integrated circuits, the Apollo Guidance Computer.[11][12]
Structure and materials
Two main instrument panels were used for Vostok and Voskhod: a control panel with switches and rotary controllers, and an instrument display panel (IDS, for Instrument Display System).[2] On Vostok and Soyuz spacecraft, the IDS Panel sits in front of the cosmonauts, above the Vzor periscope screen. As for Voskhod 1 and Voskhod 2 however, mission design compromises forced upon the designers for propaganda motivations[1] had the cosmonauts' seats rotated 90 degrees clockwise, making the reading and setting of the IDS panel less convenient.[citation needed]
Designed to be integrated into a niche in the instrument display panel, the IMP instrument's volume was about that of a big toaster [Width: 24.8 cm(9+3⁄4 in), H:22.2 cm (8+3⁄4 in), D:14.6 cm(5+3⁄4 in)]. It was the prominent feature of the IDS panel. The front panel of the IMP instrument served as the structural support for all other components; it was made of thick, machined aluminum alloy with structural protrusions.[citation needed] The mechanical components were made of brass, steel and aluminum; the globe itself was made of aluminum covered with printed paper, a typical technique for the manufacture of terrestrial globes. The enclosing cover was made of a sheet of aluminum alloy cut and soldered to shape.[citation needed]
Like most of early spacecraft's cockpit instruments, the IMP Globus was designed and tested to remain operative in a complete vacuum, in case of an accidental depressurisation of the cabin.
Displays and settings
Displays
- A terrestrial globe, with a diameter of 12.7 cm (5 inches),[citation needed] which approximate a 1:100,000,000 scale, moving in two degrees of freedom (rotation and inclination);
- Two disc-shaped indicators, one each for longitude and latitude, with markings in degrees on their edges;
- An orbit counter labelled ЧИСЛО ВИТКОВ (Number of revolutions) with three digits: two white digits for orbits and one red digit for fraction of an orbit;
- A backlit indicator below the globe that, when illuminated, displayed the text МЕСТО ПОСАДКИ (Landing Place).
Pilot settings
- One switch (on the separate Control panel) activates the instrument;[5]
- One switch (on the separate Control panel) activates a motor which displaces the indicators from the actual position relative to the Earth to the projected point of landing position, or vice versa[5]
- Two concentric knobs conjointly labelled КОРРЕКЦИЯ (Correction). The inner knob is simply labelled С, П and Л (Center, Right and Left). Selecting one of these three positions mechanically assigns the outer knob, labelled НАПРАВЛЕНИЕ ВРАЩЕНИЯ, МЕНЬШЕ and БОЛЬШЕ (Direction of rotation, Less and More) to preset one of three orbital parameters; and three corresponding one-digit indicators;[5]
- One knob marked Э presets or resets the indicators longitude position, i.e. in the equatorial plane;[5]
- One knob marked О presets or resets the indicators' position along the orbit;[5]
- One knob (missing in the picture) presets or resets the orbit counter.
Functions displayed
The moving terrestrial globe was protected by a hemispherical transparent plastic dome, on which was engraved and printed a cross-shaped sight. Under normal operations, the point visible under the cross was the point on Earth which was directly under the spacecraft at any given time. A second mode of operation, activated by the cosmonauts, advanced the globe to a position where the spacecraft would land should the
At least one Voskhod IMP's globe was customized with white paper bullets numbered from 1 to 8, along with unnumbered bullets.[13] Those relate to radio communication centers linked with Mission Control in Moscow. The unnumbered bullets refer to space control-monitoring ships.[13][14]
Operation
Prior to launch, latitude and longitude were adjusted to the precalculated coordinates of entering orbit. Right after the launch phase, once the orbit was established, its parameters were precisely measured by radar and radio telemetry from the ground. Revised settings for the IMP were then computed on the ground and communicated to the crew, which reset the instrument's three orbital Correction parameters, the equatorial longitude and the present point in the orbit using the two КОРРЕКЦИЯ knobs, the Э knob and the О knob. After this, the cosmonauts toggled the activation switch on the left-side Control panel. This last action connected the flight sequencer system's impulses to the instrument's solenoid actuator. These impulses were then converted into a slow, regular mechanical advance which cascaded through the mechanical components, effecting the computations needed to move the globe and other indicators.[citation needed]
Meanwhile, the instrument's variable resistor and cam-activated electric blade contacts modulated electrical signals from other electrical instruments through the spacecraft and its control systems, feeding them with an analog representation of the spacecraft's displacement relative to Earth coordinates. From a systems design perspective, it is remarkable, even in the early 1960s, that a mechanical system generated crucial, primary data to electrical and electronic control and telemetry systems through the spacecraft.[13]
During orbital operations, the crew periodically resynchronized the instrument's readings with ground-generated data during communication passes. On a Soyuz mission, the spacecraft has the added capability to do orbital maneuvers, and the orbital parameters on the IMP instrument had to be changed accordingly for each maneuver.[citation needed]
When the critical operation of deorbit retrorockets burn was approaching in preparation for
Mechanical computer
The IMP was a genuine mechanical computer. From the sole solenoid actuator's incremental motion, the horological mechanism derived irregular oscillating functions which in turn rotated the globe and varied its axis, and also moved its two cylindrical indicators for longitude and latitude. Some uncommon, intricate horological devices found in the IMP include cardioid-shaped cam discs, a cone-shaped cam cylinder with a cardioid cross-section and "mechanical rectifiers" which transformed an alternating motion into an analogous, but unidirectional motion (see illustrations).
The only other electric actuator used in the IMP instrument was the motor used to fast-forward the mechanism from the actual point-to-nadir to the expected landing point, some 120 degrees further east.[3]
Production, conservation and public display
A few dozen specimens at most of the Voskhod Globus instrument Versions 3 and 4 were built, including the two flown during the Voskhod 1 and Voskhod 2 missions, test articles and units flown in unmanned missions. Many of them are exhibited in various
Space-related artifacts are available for purchase on online auction sites, on specialized auctions and through specialized dealers. However, items such as Globus instruments rarely come on the market.[13]
One specimen of a Voskhod Globus IMP instrument have been the property of Canadian space-related artifact collector François Guay. It is now (2020) owned by one of the premier space hardware collectors in the world, based in the United States.[15] It has been exhibited in temporary exhibitions, notably the National Watch and Clock Museum in Columbia, Pennsylvania, US,[16] and at the Space Science Center of the Cosmodome in Laval, Quebec, Canada.
Illustrations
Elements of mechanical computing
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fig.1
-
fig.2
-
fig.3
- A combination of a conical cam, a rocker arm and a rocket arm worm screw conveyor transforms a rotary motion into an oscillation function, whose amplitude is varied by a manual setting.
- A combination which redresses an alternating motion into an analogous, unidirectional motion.
- A variable resistor rotating once every orbit returns the actual angular position within the orbit to other instruments.
See also
- Terrestrial globe
- Voskhod 1
- Voskhod 2
- Voskhod rocket, the launcher used with the Voskhod spacecraft
- Voskhod programme, including cancelled crewed missions
- Voskhod spacecraft, for which the Globus IMP 3 was specifically built
- Vostok spacecraft, instrumented with anterior versions of the IMP
References
- ^ ISBN 978-0-8130-2627-5.
- ^ a b c Тяпченко (Tiapchenko), Юрий Александрович (Yurii A.). "Information Display Systems for Russian Spacecraft: An Overview". Computing in the Soviet Space Program (Translation from Russian: Slava Gerovitch).
- ^ a b Тяпченко (Tiapchenko), Юрий Александрович (Yurii A.). "Системы отображения информации космических кораблей "Восток" и "Восход"".
- ISBN 978-0-8130-2627-5.
- ^ a b c d e f Collins, Amy Kyra. "The Panels of the Spacecraft Vostok". Vostok Control and Instrument Panel Site СОИ кк «Восток».
- ^ Tiapchenko, Yurii. "Information Display Systems for Russian Spacecraft: Generations III, IV and V". Computing in the Soviet Space Program (Translation: Slava Gerovitch).
- ISBN 978-0-7566-5641-6.
- ISBN 978-2-7613-2726-8.
- ^ a b NASA C-119162 Project Gemini Familiarization Manual, 1963, McDonnell, https://www.ibiblio.org/apollo/Documents/GeminiManualVol1Sec2.pdf
- ^ CR-123823, 63-928-130, "IBM Apollo Study Report, Volume II: LVDC", volume II of II, 10/01/1963, by IBM Federal Systems Division https://www.ibiblio.org/apollo/Documents/IBMStudyReport-63-928-130-Volume2.pdf
- ISBN 1-56347-185-X
- ISBN 978-1-62683-027-1.
- ^ a b c d music_space. "Researching and exhibiting Voskhod Globus". Hardware & Flown Items.
- ^ Collins, Amy Kyra. "Ground support". Amy's Spacecraft Vostok Control and Instrument Panel Site СОИ кк «Восток».
- ^ "Topic: Researching and exhibiting Voskhod Globus (look for SpaceAholic)".
- ^ "Time & Exploration Exhibit - NWCM". p. 52.
External links
- Researching and exhibiting Voskhod Globus on www.collectSPACE.com - Space history and artifacts.
- Cosmodome, Laval Qc (Canada) Archived 2011-11-10 at the Wayback Machine
- National Watch & Clock Museum, Columbia Pa (US)
- The Smithsonian Institution's National Air and Space Museum, Washington DC (US)
- vostoksupersite.weebly.com - Vostok instrument panels, with details about IMP instruments