In your question detail, you have mentioned that you don't really want the people to advance from industrial age, you only specifically want them to not enter the space age. There are three possibilities for this, in my opinion.
The first and simplest of the methods is to set the priorities for the people on your planet. Make them more inclined towards research which has immediate and direct material output. Chemistry, industrial physics, medicine, computers etc. Space exploration does not have any immediate material advantage at all. Heck, even we humans, after more than 50 years of launching space missions, have not obtained any material advantage out of it.
Space travel is very, very expensive and the most basic requirement for it is money. Having no material incentive in space exploration will keep the governments from spending tax money into something which looks nothing more than a scientific luxury. Similarly, corporations and banks would also be disinclined from investing into this profitless waste of money.
In this case, the leap from non space faring civilization to a space age civilization would just require a change in priorities. Maybe an asteroid composed of very rare, very precious metals would help persuade the people to launch space missions in order to obtain more of these space treasures?
Make rocket launches very difficult. This could be done by putting your colonists not on a planet, but on a moon of a large gas giant, such as Jupiter. You can easily put an Earth-sized object as a moon of a gas giant this big.
While the escape velocity of this moon would be possible to achieve, it would be incredibly difficult to obtain the escape velocity of the parent planet, thus making space missions prohibitively difficult. In this case, your people will have a strong urge to explore and travel to interplanetary space, but it would be very difficult for them to do so.
The added benefit here would be that in any point in the story, you can simply invent a new type of chemical compound that as a very high energy density, making it possible to achieve the escape velocity of the parent planet.
Make the parent star too hostile for long term space expeditions. This can be done by making the solar wind too strong (A and F type stars would be interesting choices for your parent star) to enable any manned missions anywhere out of the planet.
The added bonus of this approach would be that your people would be able to send unmanned missions into space (although those too, would be very much costlier than those of Earth, and the onboard electronics would have very little lifespans as compared to our our satellites) but would be unable to launch themselves (or any other living thing) into space. This titillating obstruction may make your story even more interesting.