Adept Rocketry

Maximum Altitude Altimeter with Deployment

ALTS1 - Price: $72.00 - Includes Modified CAB5-24 Interconnect Cable and GP-23A Battery.

ALTS1-50K - Price: $89.00 - Includes Modified CAB5-24 Interconnect Cable and GP-23A Battery.

The ALTS1 Altimeter with Deployment is a maximum altitude altimeter that measures and reports the maximum above-ground altitude value obtained during a rocket's flight. The ALTS1 also has an altitude controlled deployment switch that is typically used to fire a deployment charge, based on altitude. In one mode the charge fires when the rocket reaches its maximum altitude (apogee), or the charge may be programmed to fire when the rocket descends to 500 feet above ground. The most common usage is to deploy a main parachute at apogee.

This device is used in rockets that will reach at least 300 feet altitude. The deployment switch may be used, or the device may be used as a maximum altitude altimeter only. The ALTS1 may be used in any rocket configuration including multistage rockets, in which case maximum altitude information about a particular stage can be obtained by placing the device in the particular stage of interest. Or individual ALTS1 units (or other altimeter devices) may be placed in each stage of interest to report the maximum altitudes obtained by each stage, and/or to handle deployment for each stage.

The ALTS1 precisely captures the highest altitude obtained during a flight to a maximum of 15,000 feet above sea level. The extended ALTS1-50K version functions to 50,000 feet above sea level. The maximum value obtained above the local ground-zero altitude is precisely measured and reported in one-foot increments (one-foot resolution).

The ALTS1 measures 0.9” wide by 0.65” thick by 4.25” long. It fits inside a tube with a minimum ID of 24 mm, or 0.95 inch. The device weighs only 24 grams (0.85 ounce), including the battery. It uses a 12-volt alkaline lighter battery with a battery life up to 6 hours, so you need not be concerned about how long your rocket sits on the launchpad after the unit is powered up. The ALTS1 is a totally stand-alone device including the battery holder, arming mechanism, and current source for firing a deployment charge. Nothing more is required except for the wires (interconnect cable) that connect to the On-Off switch and to the deployment charge.

The altimeter uses a custom absolute pressure device to precisely measure altitude values up to 15,000 (or 50,000) feet in one-foot increments. It uses a 16-bit logarithmic analog-to-digital converter to precisely (one-foot resolution) measure the nonlinear pressure versus altitude relationship over this large altitude range. Once powered up, the ALTS1 reports whether or not the deployment charge has continuity. It also constantly measures the ground-level altitude and waits for a quick 300-foot change upward. It then captures the maximum altitude obtained above ground zero. If programmed to do so the ALTS1 fires the deployment switch at the very moment when the rocket reaches the maximum altitude. Or it may be programmed to fire the deployment switch when the descending altitude reaches 500 feet above the ground. The ALTS1 uses the copyrighted and patented and trade marked technique of beeping out (blinking on some models) a value to report the maximum altitude value. The beeps can be heard even when the unit is still inside the rocket. The rocketeer knows the maximum altitude as soon as he/she picks it up, or just gets close to it. Note: the ALTS1 cannot be used for, and will not function for, maximum altitudes less than 300 feet.


  • Altitude Capability: to 15,000 feet Above Ground Level (AGL), to limit of 15,000 feet Above Sea Level (ASL) for the standard version (50,000 feet for the Extended ALTS1-50K Version).
  • Lowest Maximum Altitude Readable: 300 feet above ground. Liftoff is detected when the altitude quickly increases by 300 feet.
  • Mach Compatible; the ALTS1 uses Adept's proprietary Real Time Dynamic Lockout™ system that tracks speed in real time to ignore pressure glitches that occur when transitioning through the sound barrier, both in and out. This system is possible due to the extreme precision of one-foot resolution measurements.
  • Resolution of Measurement: one foot; system uses a logarithmic 16-bit A-to-D converter.
  • Calibration Accuracy Over Full Range:  +/- 1%, typical.
  • Uses 12-volt lighter battery and has a large integral capacitor to fire flashbulb or low-current electric match charges.
  • Battery Life: up to 6 hours.
  • Piezo beeper reports altitude and operational status including the continuity of the deployment device. One repeating beep if the deployment device does not have continuity, and two beeps repeating when the deployment does have continuity.
  • Output Switch may be programmed to fire when the altitude reaches maximum (apogee), or it may be programmed to fire during descent at 500 feet above the ground. This is user selectable via a single programming jumper.
  • Measures 0.9” wide by 0.65” thick by 4.25” long and fits inside a tube with a minimum ID of 24 mm, or 0.95 inch.
  • Weighs only 24 grams (0.85 ounce) with battery installed.
  • Accessories Required: one 12-volt alkaline lighter battery, and one cable (Adept CAB5-xx series) to connect an On-Off switch and to the deployment charge.


CAB5-24 Interconnect Cable
Price: $6.25 - 24 inches long. Connects ALTS1 to On-Off Switch and to Deployment Charge.
CAB5-12 Interconnect Cable
Price: $4.99 - 12 inches long.
CAB5-36 Interconnect Cable
Price: $7.29 - 36 inches long.

Additional GP-23A Alkaline Lighter Battery; Price: $2.25.

GP-23A50 Alkaline Lighter Batteries (box of 50 at 50% Discount); Price: $56.25.

Shorting Jumpers are used to connect two connecter pins together in order to turn on the power for some of the Adept devices. Shorting Jumpers are also used on some devices to program certain values or functions. One jumper is used on the ALTS1 to program the value for the Output Function, to fire at apogee when the jumper is not installed, and to fire at 500 feet above ground when the jumper is installed.

Shorting Jumpers
Price: $1.39 per pack of 10.

VCK2 Vacuum Chamber, Complete with Bottle.
Price: $16.79. Use for simulating flights, and for testing Altimeters with or without deployment.

Electronic Instrumentation is not compatible with the fumes and residue created by rocket motors and deployment charges. Seal holes and gaps in bulkheads and such with epoxy or removable putty.

Tac'N Stik Removable and Reusable Putty
Price: $1.99 per 2 ounce pack.

The perfect mate for the ALTS1 when used in a dual redundancy backup system is the DCS1. The ALTS1 would function as the primary device to measure altitude and to control deployment. The DCS1 would function as the redundant backup device to also control deployment If one of the devices is programmed to fire a drogue chute at apogee, and the other is programmed to fire the main parachute at 500 feet above ground, then the technique of Dual Deployment™ can be implemented.

DCS1 Deployment Controller™
Price: $59.00 - Includes Modified (no yellow wire) CAB5-24 Interconnect Cable and GP-23A Battery.

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